In [1]: import numpy as np In [2]: a = np.random.randint (0, 10, (2, 1, 10, 10, 3)) In [3]: np.squeeze (a, axis=1).shape Out [3]: (2, 10, 10, 3) So be sure to set the axis=1 argument. Then just pass the updated array as you were doing. Thanks, I found a line in the image prep code where an additional dimension was added with the comment "adding ...